I. Field of the Invention
This invention relates to apparatus and methods for geophysical prospecting by propagating seismic waves in the earth and moe particularly to apparatus of this character adapted for use in a marine environment to generate shear waves either alone or in combination with compressional waves.
II. Prior Art
Existing underwater seismic devices are well known which are designed to produce compressional waves in the water, which in turn are transmitted to the marine bottom and there propagated in the earth. Such devices, however, are clearly incapable of generating shear waves.
In order to propagate shear waves in a marine environment, means must be devised for coupling the energy of a seismic source directly into the marine bottom rather than through the medium of the water. This is the basic problem and objective to which applicant's invention is addressed.